Ignition distributor with a support plate for the contact assembly held in position by zone resilience

ABSTRACT

An ignition distributor including a casing, a rotatable shaft extending axially within the casing of the distributor, and carrying the rotor arm of the distributor, and a plate supported within the casing and carrying the contact breaker assembly of the distributor, said plate being engaged with the inner surface of the casing by virtue of its own resilience, the plate being flexed during insertion into the casing and the casing being shaped to locate the plate in its correct position.

United States Patent Cooksey 1 June 6, 1972 [54] IGNITION DISTRIBUTOR WITH A [56] References Cited SUPPORT PLATE FOR THE CONTACT UNITED STATES PATENTS ASSEMBLY HELD IN POSITION BY ZONE RESILIENCE 2,075,904 4/1937 Lang et al ..200/l9 2,835,755 5/1958 Filko ..200/3l X [72] Inventor: William Harold Cooksey, Walsall, England Primary Examiner-Robert K. Schaefer [73] Asslgnee' P Lucas (Industries) Lmmed Assistant Examiner-Robert A. Vanderhye mmgham England Attorney-Holman, Glascock, Downing & Seebold [22] Filed: Aug. 1, 1967 [57] ABSTRACT [2]] Appl. No.: 657,630 I An ignition distributor mcludmg a casing, a rotatable shaft extending axially within the casing of the distributor, and carry- [30] Foreign Application Priority Data ing the rotor arm of the distributor, and a plate supported I within the casing and carrying the contact breaker assembly of Aug. 23, 1966 Great Britain... ..'37,673/66 the distributor Said plate being engaged with the inner surface of the casing by virtue of its own resilience, the plate being 521 [15.0 ....200/19, 200/31,200 22 flexed during insertion into the casing and the casing being [5| I [I'll- CI. H0111 shaped to locate the plate in its correct position [58] Field of Search ..200/l9, 22, 25, 29, 31

7 Claims, 3 Drawing Figures PATENTEDJUN 6 I912 SHEET 2 OF 2 groove 14. A box-like structure This invention relates to ignition distributors for use in road vehicles, of the kind including a casing, a rotatable shaft extending axially within the casing and carrying the rotor arm of the distributor, and a plate supported within the casing and carrying the contact breaker assembly of the distributor, rotation of said shaft serving to operate the contact breaker assembly.

According to the invention in a distributor of the kind specified said plate is engaged with the inner surface of the casing by virtue of its own resilience, the plate being flexed during insertion into the casing and the casing being shaped to locatethe plate in its correct position.

One example of the invention isillustrated in the accompanying drawing wherein:

FIG. 1 is a sectional view of a distributor,

FIG. 2 is a sectional view of the casing of a distributor takenin a plane at right angles to the plane of FIG. 1, with parts thereof omitted for clarity and,

FIG. 3 is a plan view of a plate in FIG. 1 with the contact breaker assembly omitted for clarity.

Referring to the drawings the distributor includes a hollow cylindrical casing 1 1 having a hollow axialextension 12 within which is journalled a shaft 13. The shaft 13 extends axially within the casing ll and is formed with a cam surface 13a. The shaft carries at its upper end the rotor arm of the distributor. The casing 11 is closed in use by an insulating cap 1 1a carrying a plurality of contacts with which the rotor arm coacts as the shaft 13 is rotated.

The casing 11 is formed with an internal circumferential groove 14 (FIG. 2) with which is engaged a substantially arcuate plate 15. The plate 15 is moulded in a synthetic resin and is shaped to partially surround the shaft 13. The plate 15 is engaged with casing by flexing its ends towards one another, inserting the flexed plate into the casing and allowing it to spring back to its original shape with its outer edges engaged in the 16 is moulded integrally with the plate 15 and in use a capacitor 16a is housed in the structure 16 and encapsulated therein by known techniques. One side of the capacitor is earthed through a lead 17 connected to the casing while the other side of the capacitor is connected through a terminal blade 18 which extends through a slot in the casing 11, and through the primary winding of an ignition coil to a d.c. source.

The plate 15 is moulded with an extension 19 which is joined to the main pan of the plate 15 by an integral hinge 21 in which is formed a pair of necks 22, the arrangement being such that the extension 19 can be moved relative to the plate 15 as allowed by flexure of the hinge 21 at the necks 22. The extension 19 is moulded with an axially extending post 23 having therein a diametrically extending screw-threaded bore 24. The extension 19 is further formed with a pair of flexible arms 25 which in use engage the casing 1 1 and thereafter act to bias the extension radially away from the casing. A screw 26 is engaged with the bore 24 and extends through a stepped bore 27 in the casing, the arrangement being such that rotation of the screw 26 in one direction moves the extension 19, against the action of the arms 25, towards the casing, while rotation of the screw 26 in the other direction allows the extension to be moved by the arms 25 away from the casing.

Slidably supported on the plate 15 is an annular conductive plate 28 which carries the fixed and movable contacts 29, 31 respectively of the contact breaker assembly. The movable contact 31 is pivoted on, but insulated from the plate 28 and includes an insulating cam follower 32 which engages the cam surface 13a of the shaft 13. The movable contact 31 is urged by a spring 33 in a direction to engage the cam follower 32 with the cam surface 13a, rotation of the shaft 13 thereby serving to open and close the contacts 29, 31. The plate 28 is formed with a hole through which the post 23 extends thereby pivotally interconnecting the extension 19 and the plate 28.

Thus by rotating the screw 26 screw 26 is kept to a minimum. The plate 28 is earthed through a conductive lead connected at one end to the plate 28 and connected at its other end to a spring clip 35 which is trapped in contact with the casing 1 l by the plate 15.

The plate 28 is maintained in engagement with the plate 15 by a U-shaped spring clip 34, the two free ends of the clip being engaged in holes in the plate 28 while the base of the clip is engaged under a rigid flap 23a at the upper end of the post 23.

It will be appreciated that the casing 11 and/or the screw 26 the pitch of the screw 26 could be chosen so that a convenient number of rotations of the screw result in a desired adjustment of the contact breaker gap, or dwell angle. Moreover, it will further be appreciated that the fixed contact 29 is earthed through the plate 28 and the movable contact 31 is connected through the spring 33, a lead 36 and the terminal blade 18 to the primary winding of the ignition coil, so that opening and closing of the contacts 29, 31 breaks and makes the circuit through the primary winding.

In order to enhance the resilience of the plate 15, the plate 15 can incorporate a metal spring, the spring either being secured to, or moulded into, the plate 15, as to become part thereof.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An ignition distributor comprising in combination a casing, a rotatable shaft extending axially within the casing, a rotor arm carried by said shaft, a circumferential groove within the inner surface of said casing, a support plate having its outer periphery engaged within said groove, said support plate being resilient, and being capable of being flexed during insertion into the casing so permitting said plate to be engaged in said groove, a contact breaker assembly supported by said plate within said casing, said contact breaker assembly including a fixed contact and a movable contact, and said contacts being open and closed by rotation of said shaft, a capacitor connected electrically across said contacts, a compartment formed integrally with said plate, said capacitor being housed within said compartment, and encapsulating means sealing said capacitor within said compartment.

2. A distributor as claimed in claim 1 wherein the contact breaker assembly comprises a second plate slidable along said plate and carrying the fixed contact and movable contact, sliding movement of the second plate on said plate serving to move both contacts towards or away from said shaft to vary the amount by which the contacts can be opened in response to rotation of said shaft, said plate being formed with a hinged portion with which the second plate is engaged so that movein claim 2 wherein said hinged portion is formed with an upstanding post with which the second plate is pivotally engaged.

4. A distributor as claimed in claim 2 including a spring clip acting between said plate and the second plate and urging the second plate into contact with said plate.

5. A distributor as claimed in claim 2 wherein said hinge portion is engaged by a screw which is rotatably received in the casing, the head of the screw engaging an outer surface of the casing so that rotation of said screw in one direction serves to move said hinged part towards the head of the screw against resilient means.

6. A distributor as claimed in claim 5 wherein said resilient means includes a pair of resilient arms integral with said hinged portion, said arms engaging the inner surface of the casing and resisting said movement of the hinged portion.

7. A distributor as claimed in claim 5 wherein the periphery 

1. An ignition distributor comprising in combination a casing, a rotatable shaft extending axially within the casing, a rotor arm carried by said shaft, a circumferential groove within the inner surface of said casing, a support plate having its outer periphery engaged within said groove, said support plate being resilient, and being capable of being flexed during insertion into the casing so permitting said plate to be engaged in said groove, a contact breaker assembly supported by said plate within said casing, said contact breaker assembly including a fixed contact and a movable contact, and said contacts being open and closed by rotation of said shaft, a capacitor connected electrically across said contacts, a compartment formed integrally with said plate, said capacitor bEing housed within said compartment, and encapsulating means sealing said capacitor within said compartment.
 2. A distributor as claimed in claim 1 wherein the contact breaker assembly comprises a second plate slidable along said plate and carrying the fixed contact and movable contact, sliding movement of the second plate on said plate serving to move both contacts towards or away from said shaft to vary the amount by which the contacts can be opened in response to rotation of said shaft, said plate being formed with a hinged portion with which the second plate is engaged so that movements of the hinged portion are transmitted to the second plate so as to alter the distance by which said contacts are opened in response to rotation of said shaft.
 3. A distributor as claimed in claim 2 wherein said hinged portion is formed with an upstanding post with which the second plate is pivotally engaged.
 4. A distributor as claimed in claim 2 including a spring clip acting between said plate and the second plate and urging the second plate into contact with said plate.
 5. A distributor as claimed in claim 2 wherein said hinge portion is engaged by a screw which is rotatably received in the casing, the head of the screw engaging an outer surface of the casing so that rotation of said screw in one direction serves to move said hinged part towards the head of the screw against resilient means.
 6. A distributor as claimed in claim 5 wherein said resilient means includes a pair of resilient arms integral with said hinged portion, said arms engaging the inner surface of the casing and resisting said movement of the hinged portion.
 7. A distributor as claimed in claim 5 wherein the periphery of the screw and the casing are calibrated so that a measured rotation of the screw results in a predetermined adjustment of the amount by which said contacts are opened in response to rotation of said shaft. 